1. Field of the Invention
This invention relates to reference information included in captured digital signals, and more specifically to a digital reference information providing a baseline for determining and measuring audio and video signal changes in the post production and display processes.
2. Description of the Prior Art
The move to capture images electronically for cinema productions closely resemble the evolution of television production moving from film to video based capture technologies. Tools developed for both film and video provided the post production processes the ability to restore the original look of the scene by using various tools and procedures. For the film production, a color chart was photographed at the head of each scene to assist in color balance during the film to tape transfer. Video productions may use a color bar reference at the head of the program material to assist in proper set-up of playback levels. Both systems may work for the intended media.
Unlike film, an electronic camera offers the ability to see the result immediately on a picture monitor. Observing recent productions, set lighting and aperture were adjusted based on the image that was displayed on a waveform and picture monitor near the camera. Upon being satisfied that the scene was xe2x80x9ccorrectxe2x80x9d, the production would proceed and the image recorded on a High Definition Tape recorder. What may be important to the director and cinematographer as far as subtle detail in the shadows and lace curtains in a window may be overlooked in later steps of post-production. Rarely will both detail in shadows, and detail in backlit windows survive together, either one or the other are normally clipped during the post process. But what is needed is test signal data that may reside along with the active picture and or sound data that may identify benchmark image or sound characteristics.
The present invention may provide a technique for managing the production, post-production and distribution of audio-visual projects to permit accurate management of production values to enable accurate and measurable control. Test signal data may assist the operator in insuring the levels are indeed set to the intended look in the event of any creative lighting applied or effects used that would create an unnatural look to the scene. The test signal data may encompass elements that determine resolution, White level, Black level, Grey steps, Frequency response and linearity as well as sound parameters. Chroma channels may exhibit similar signals including a bar pattern that can be used to insure the best colorimetry is maintained. Standard signals may also improve compositing and cross media transfers without extraordinary efforts to match production values.
In another aspect of the present invention, a test signal may be inserted on an active but unused line of video to track and monitor the video image""s signal level and quality throughout the mastering and replication process. The image quality is therefore measurable by referencing this signal. This same model can be applied to audio and Digital Cinema.
When capturing an image with a digital cinema camera, test signal data can be inserted and recorded along with the active picture and sound. This test signal data may serve as a reference for the sound and picture quality and associated technical parameters. The post production process may involve such things as xe2x80x9ctimingxe2x80x9d or changes to color balance and component signal levels in order to produce finely tuned images and sound. At any time throughout the production and post-production processes, one can return a scene to the original image capture levels by referencing the test signal data and adjusting levels to their original state. For scenes used in special effects, the test signal data can be used to control levels and maintain continuity between like scenes and composited images. Certain automated functions could be implemented in conjunction with the test signal data in much the same way as VIRS works in consumer television today to control signal levels between the origination site and the local broadcast station.
Applications of this test signal data in the creation of the digital master may include:
Creation of the High Definition or Super High Definition Digital Master;
From Digital source to Digital
From Digital source to Film
From Film source to Digital
It should be possible to integrate the test signal data generator into the recording device on the set, therefore eliminating the need for a separate piece of equipment to generate the test signal data.
In a still further aspect of the present invention, test signals may be added to entertainment distributions such as analog media, digital media and optical media. The test signals may be used to align the home entertainment system of a user to reproduce the intended theatrical performance.
In another still further aspect of the present invention, test signal data may be added to entertainment venue distributions using analog media, digital media and transmissions, and optical media and transmissions however distributed. The test signal data may be used to align the venue entertainment system to reproduce the intended performance and one or more feedback channels may provide the distributor or creator information or control of the characteristics of a performance.
These and other features and advantages of this invention will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features of the invention, like numerals referring to like features throughout both the drawings and the description.